Stop mechanism for machine tools



G. H. WILLIAMS April 17, 1945.

STOP MECHANISM FOR MACHINE TOOLS lFiled sept'. 4, 194s 2 sheets-sheet 1 INVENTOR. 6km/NE Win/AMS AT1-0R1r Y.

April 17, 1945.4

STOP MECHANISM FOR MACHINE TOOLS Filed Sept. 4 1943 2 Sheets-Sheet 2 56 18 6km/NE TV/'LL/MS 19 lNvENToR. -40 20 15 G. H. WILLIAMS 2,373,934 l y l AT'roR EY.

Patented Apr. 17, 1945 srorzMnonANrsM Fon-Mmmm; .'rooLs lGrlfynn SH. Williams, Huntington LPaik, lif., as l .isixnuratoulxelsonManufacturingingflios geles,QCnlif., aworporation oIfsGalifornia Alllllicationseptember 4, 1943, Serial 'No.'501'3269 rilsflaims. (Glan-Mi 'with'.quantity production problems;

.P rior .to my invention the. conventional form of lstop .consisted merely .of a clamp member or set ,screw device which was adapted tobe clamped vor otherwise .secured to the guiding ways in the path ofthe carriage or `tool/,toerrest motion Aof 'the carriage or .tool .at *the .desired point. 'Such' stops are not entirely satisfactory because `Ithey are diicult to `set `with suflicient rigidity 'to prevent Slipping and a consequent [loss .accuracy in the parts ,produced bythe ,machine and,` second, 'because '.of the `diiliciilty )forthfin 'theprecedingfparagraphs which includes .also r.a .means ior -making .micrometer adjustments to lthe stop .location after .thestop is set .andwithout releasing the..stop.

1t is .astill further .object of my invention .to provide a .stop device of the .character-.herein- .before referred to Which'theinicrometer `vad-r jjusting device is .operable withoutinterfering. with the accuracy of indication Agiven'loy the indicating dials .of .the carriage .or tool feeding mechanism.

It .'issan .additional obj-ect ofmy invention to provide .a .stop device ofthe character lsetforth j in the preceding .paragraphs which includes .also a means .for preventing the setting oi the .stop inthe absence of 4a .deliberataintended attempt to doso.

fOther objects and advantages of .my invention will ,befapparent from .a study of the following specification, read in connection .with thexaccompanyingdrawings, wherein:

` A IFig; l `is .a longitudinal sectional view .of the involvedinsetting such .stops withfthe uprecision required. y

.In mamr machining operations as, for example, a conventional turning operation 'on `an 4en gine lathe, it is necessary .that astop such'as a cross .feed stop be setto within `an .accuracy of, plus or minusone or two'looo of aninchandrnot infrenquently .with a tolerance as small as '/o 000 of an inch. This is a vdifllcult and time consuming .operation "with `conventional istop mechanisms requiring the stop to he "prelimi- .narily set, a test run to be made andthe stop to be adjusted and repeated tests and adjustments vto be made until the stopis ilnally locatedin `the desired position. n

'It is, therefore an object of my invention to 'overcome the above noted disadvantagesbyproviding a stop device for carriage or 'tool {feeding mechanisms of "machiner rtools which "may Abe' set at a desired locationby Amoving the tool or carriage to ythat'location and then moving `a .n

.to provide Aa stop fdevioe of the .character setf crossfeed ,mechanism (of a .conventional engine latheillustrating the preferred embodiment 'of the stop deviceof my invention;

.Fig.2 .comprises anenlarged viewA of thestopk 'device :included `in.l1"ijg.11 and illustrating the stop in its engaged ,or tool `arresting position;

Fig. Bis a crosssectional view taken substantially .along 'the line vIII-III of`Fig..'1 showing Vdetails .gf construction ofv astop housing mem- "Fig 4 is a viewsimuar to Fig. 3 but showing fthe details of construction ofthe 4opposite end of 'the stop housing `member;

SFig. "5.is aside elevational view of the housing'for Lthe'stop deviceshowing the control mem.- 'berused'to set and release the stop;

'Fig 6Lis 'a cross..jsec tional .view takensubstantially along 4the 'linieVI-'VIE .of '.Fig. l .and illustrating ',thegjdetails fof construction .of the stop device, A'6 showing the stop in its .engaged or set position; y

Fig'l is a'view..simi1ar to Fig. '.6 vbutillustrating ith-e positions of y'the parts when the Vcontrol A 'device is'moved lto disengage `or release the. stopn...

Referring'tothe drawings,`I have illustrated in Eig.y 1 .a conventional carriage or tool feeding mechanism, l"the particular vconstruction which is Iillus'tralted'inFig. '1 :comprising the cross feed for a' conventional engine lathe. :This `construction ,isbu'ilt into'the'lathe' carriage, the pertinent 4portion'of which isf'indicated generally by theirefer ence 'characterliinlg 1.` I ,y

ment the location of the carriage relative to t'lfiejy turning axis of the lathe is indicated.

According to the present invention, the lathe" carriage I is provided with an extension vor case portion I3 within which the bearing. 'I is mounted A and which is longitudinally bored as shown at I4 to receive a rotatable stop yhousing I5. The stop housing I5 comprises a cylindrical member which is journaled for rotation coaxially with the cross feed screw 6 within the bore I4. The housing I5 includes end closure portions I6 and I'I and is screw threaded interiorly'as indicated at I8.v Engaged with the screw threads I8 is a similarly male threaded stop element I9, this latter element being bored to encircle thefeed screw 6 and interiorly splined to be drivably and slidably engaged with the cross feed screws 6 through the medium of splines formed on the exterior of the screw 6.

The stop member I9 is characterized by front 'Y and rear radial faces 2i and 22 from each of which protrudes axially extending lug members 23 and 24 each preferably formed integrally with the stop member I9.' Similarradially extending y lugs 25 and 26 are formed on the closure members IS and I'I of the rotatable housing I5, the lug 25 being preferably formed as by milling a radial slot 2'I in one end of the housing I5 disposed to cut away the inner portion of the elosure I6, the radial slot 27 having an angular scopev of approximately 300 to leave an axiallyv protruding portion which constitutes the stop lug 25. This construction is illustratedv in Figs. 3 and 4.

.With this constructionl rotation 'of the cross feed screw-6 will result in rotation of the Stop member I9. If, during this rotation, the'stop housing I5 is not rotated, the stopy member I9 will be moved axially along the splines 20 due to the threaded engagement at I8 between'the st op element I9 and the stop housing I5. If,` on the other hand, the stop housing I5 is allowed to rotate, the stop element I9 will remain stationary as regards axial movement andthe cross feed. `screw 6 may be rotated to any desired extent.

By holding the stop housing I5 against rotation, the stop member I9 may be caused to rotate within the stop member I5 in response to yrotation of the hand-wheel 9 and thereby be moved axially within the housing I5. This axial movement may be continued until the element I9 has moved to such a position that continued rotation of the cross feed screw 6 will bring the side surfaces of one of the lugs 23 or 24 into engagement with a side surface of the stopmembers 25v or 26. When this condition obtains, the cross feed screw 6 will be restrained against further movement.

In order to permitthe stop housing I5 to be held against rotation or released forjfree rotation as desired, I form on the outer peripheryl thereof worm gear teeth 28 which are adapted to .be 'en'- gaged by a worm 29. The worm 29 is secured to a transversely extending shaft 30 vwhich 'isfin turn journaled for rotation within a sleeve 3I.

The sleeve 3| is journaled for angular movement as by extending the same into a counterbore 32 formed in the housing I3 and held against axial movement-.vas by providing a threaded engagement between a reduced diameter portion 33 thereof and a threaded bore 34 constituting an extension of the counterbore 32. The threaded engagement 33--34 is preferably made a close but free fit so that the sleeve 3I may be held against unintended axial movement but mounted for free angular movement.

The axis of rotation of the sleeve 3I is offset oreccentrically disposed with respect to the shaft 30 so that as the sleeve 3I is moved through an angle of approximately the worm 29 will be moved from a position such as that illustrated in Fig. 6 in which the worm 29 engages the worm gear teeth 28 to a released position such as that illustrated in Fig. 7 in which the worm 29 is disposed a sufficient distance away from the housing I5fas`to permit the same to be freely rotated.

` In order to insure that the sleeve 3I will orld inarilybe positioned in either of the two posithe spring 39 in order to move the sleeve 3I between the two positions illustrated in Figs. 6 and V7 and will thus be resiliently held against movement away from these two positions. To facilitate movement of the sleeve 3| between the two` described positions, a downwardly and outwardly extending control handle 4I is preferably provided.

Theshaft 39 is preferably extended through the sleeve v3l to receive upon its outermost end an` adjusting knob 42 by means of which the worm 29 may be rotated when in the engaged position illustrated in Fig. 6. An angular shift- Ving of the knob 42 will thus result in a very slight yangular movement of the housing I5 and an equal shifting of the location of the stops 25 and 26, thus'permitting extremely` accurate and fine adjustments to be made to the position of the stops.

erator decides to so set the stop on the cross feed screw 6 as to prevent inward movement of the compound rest 2 beyond a predetermined position yas' indicated by ,the dial I0, he first moves the handwheel 9 in a direction to retract the compound rest 2 vor move the same outwardly. This movement is4 continued for an amount necessary totake the' slack outof the stop mechanism and bring the stopk23 into engagement with the stop lug' 25`Aan`d rotate the stop housing I5, this operation'ybeing performed with the stop control member 4I lin the position illustratedk in Fig. '7

,positionjasindicated byV the dial I0 where it is 'desired' to fix the stop so as to prevent further gera-934 inward-.movement 'I-hecontrol handleblfl`- is then moved to: ytlie-fst'op. engaging position .illustrated i-Dnning the .mcvementrof the .handwheel tothe desiredposition, the stop-member I 9 Vhas been .rotatedwithin-f the stop :housing .l tobring the ystop 24 against theA lug 426-. When; the control :member midis-moved to 'stop engaging position, the housing@ |15. -is heldz' against. rotation, .andi-further' rotation; of the cross zf-e'edfscrew 6' is. prevented by reason-off' the engagement ofthe stop .24 withtheflug .2-6.,

.I Inft'heormr'of the, deviceishown-the handwheel 9 may be rotated in= the opposite or retracting directionf.fori'hierzturnasucrr anzcperation resulting .inzrotatinn of the stop memberlg within the `stop :housing t5 and itstaxial movement withinl tthezhousing: resulting fromthe. threaded/.engage- ,mentz i8. .Five-turnszons the crossv feed screw l6 will retractthe stop'm'ember i9- to. apoint where '-f the fstop- Z3' engages the lug 225. Upon reverse .rotationsof the handwheels'the stop-'member I9 will: again befed forwardly as itis rotated within the: stop housing I5', lthis rotation of the stop :member 1:9: and the crossfee'd screw- Bibeing arrested when the stop 24 again engages the flug '26.

I.nthe eventit is 4found that the stop has not been` set with the desired precision, the f position of the. same may :be adjusted byj use of the adjusting .knob 1422!. tate the-stop housing lland' shift the'position of the ylug'iZU to permit a slightlyY greater or lesser amount ofmovement of the handwheelS, depending `upon th'edirect-ion'in which theadjustment 'isfma'de.`

In the event it is desired to -so locatethe stop jpred'etermined point because of the engagement ofthe stop 23`fwith the lug 25.

At vthe sametime inward movement from the stop position an amount corresponding tove turns of the `handwheel '9 will be permitted;

It willbe noted that the teeth of the worm gear 2B land-worm 2-'9 are sharper than conventional lgear teeth to facilitate the readymeshing of the worm and` worm geariasthey are engaged.

- From the foregoing it will be observed that I.

have provided a stop device for carriage or tool f feeding mechanisms. which may be readily and .rapidlyset at any'desi'red location and with any desired accuracy.

It will be further noted thai-l adjustments in the location of the stop may be readily made by means of the adjusting knob 42 and that such adjustments do not change the validity of the position indications given by the cross feed dial I0.

In the form shown, ve turns of the handwheel 9 between inward and outward stops is permitted. This distance may, of course, be increased or decreased as design considerations indicate to be desirable. f

It will also be noted that when the stop control member is in the disengaged position, the entire stop mechanism floats within the housing and rotates with the cross feed screw 6 so as to in no way hamper movement of the compound rest, 2, the latter being permitted the same full free travel Rotation of4 this knob 4will ro- 1 stop mechanism of'-.myinvention..

,n While. Lhaveshowcn anda-described the preferred f n emlcodlmerrt of my .inventiom I- vdo Anot-desire t0 be limited to any of the details.A of' construction shown or described herein,-exceptasdefined in the appendedl claims. .l i

Lentini.; l .g

' i. Inra stop. device..fo1-: amachine tool including acarriage having. ahousingz enclosing a rotatable `screw* vfor moving. said carriage, the combination of.: a movablastopmember.engaged with .said f screw means torba-rotatedtherewith;. afstationary stop-member. disposed-,inY at position to-be engaged byfsaidymovable-fstop memberiand Varrest rotation of. said screw,.said stationaryfstop member being mounted Linrsaid: housing for rotation `with .said movable stop.member; and means: for selectively releasing and-.holding said stationarystop member against rotation. i

'2. :Inaistopldevice for al-machine tool including ,a carriage andzarotatable screw for .moving said carriage, thecombination of: ar stop member rotatable with said rotatable screw ai stophousing. mountedtor rotation with said stop member and-.including.aportionengageable by said stop y member; control Ameansioperable to hold said stop housing against .rotation; and adjustment means associated withsaid control means'andwoperable ini said stop engaging .positionof said `control means to shiftrthe position. of. said stophousing.

.3. In.a...stopdevice lfor a. machine tool includ- .ing a. carriage and avrotatablefscrew .for `moving lsaidcarriage, the v,combination of.: .a .movable .stop member. vdrivably.' engaged lwitlt said screw; v.astationarfy stop-.member mounted for move- .ment to'anydesired position corresponding to a selected.position of saidV carriage; control` means for selec-tively releasing yandV lockingsaid sta'- Jtionarystop member. against movement; and adjustment means associated with said control means and operable to shift the positi'on'of said stationaryv stop member without releasing ythe Same.

4. vInastop device for amachine tool includ- /ingza carriage, a rotatable screw for moving said Acarriageand-.a dial on said screw for indicating the-locatiorroff said carriage,A the combinationof Yarg-movable stopmember drivably engaged with said screw *to-be rota-tedi'fherewithjv aalstationary stop member -disposed .in a position. to beenrgagedbysaid.;movable stop memberj-and arrest .movement of said screw, said stationary stop' member being mounted for movement toany desired. positioncorrespondingl to a selected posiy tionofv saidy carriage vas indicated 'by said dial;

vcontrol means4 operable to selectively *release and hold said stationary stop member against movement; and adjustment means associated with said control means and operable in the Vstop hold- Y.

ing position of said control means to shift the location of said stationary stop means, said adjustment being operable without aiecting the validity of the carriage position'indication given by said dial.

5. "In a stop'device for a machine vtool includ-A "range isyfoumifcnmachines not:employingV the wheel, whereby said worm wheel may be rotated to move the same from a position spaced from said worm gear teeth to a position engaging said worm gear teethv and holding said stop housing against rotation.

6. In a stop device for a machine tool including a carriage and a rotatable screw for moving said carriage, the combination of: a cylindrical member mounted on said screw coaxially therewith for rotation with saidscrew and for sliding movement therealong, said cylindrical member having external screw threads formed on the exterior thereof and disposed coaxially with said screw; a stop housing mounted for independent rotation coaxially with said screw, said stop'housing being internally screw threaded to receive said screw threads on said cylindrical member; means on said cylindrical member dening an axially extending stop lug; means on said stop housing defining an axially extending stop lug disposed in a position to be engaged by the stop lug on said cylindrical member; and means for selectively releasing and holding said stop housing against rotation. '7. In a stop device for a machine tool including a carriage and a rotatable screw for moving said carriage, the combination of: a cylindrical member mounted on said screw coaxially therewith for rotation with s'aid screw and for sliding movement therealong, said cylindrical member having external screw threads formed on the exterior thereof and disposed coaxially with said screw; a stop housing mounted for independent rotation coaxially with said screw, said stop housing being internally screw threaded to receive said screw threads on said cylindrical member; means on said cylindrical member dening an axially extending stop lug; means on said stop housing defining an axially extending stop lug disposed in a position to be engaged by the stop lug on said cylindrical member, said stop housing having worm gear teeth formed on the exterior periphery thereof; a worm mounted for rotation about an axis eccentrically disposed with respect to said worm, whereby rotation of said worm about said axis moves said worm from a position spaced from said stop housing to a position engaging said worm with said worm gear teeth to hold said stop housing against rotation; and control means for rotating said worm about said axis.

8. In a stop device for a machine tool including a carriage and a rotatable screw -for moving said carriage, the combination of: a cylindrical member mounted on said screw coaxially therewith for rotation with said screw and for sliding movement therealong, said cylindrical member having external screw threads formed on the exterior thereof and disposed coaxially with said screw; a stop housing mounted for independent rotation coaxially with said screw, said stop housing being internally screw threaded to receive said screw threads on said cylindrical member; means on said cylindrical member defining an axially extending stop lug; means on said stop housing defining an axially extending stop lug disposed in a position to be engaged by the stop lug on said cylindrical member, said stop housing having Worm gear teeth formed on the exterior periphery thereof; a worm mounted for rotation about an axis eccentrically disposed with respect tok said worm, whereby rotation of said worm about said axis moves said worm from a position spaced from said stop housing to a position engaging said worm with said worm gear teeth to hold said stop housing against rotation; control means for rotating said worm about said axis; means mounting said worm about a second axis disposed concentrically with respect to said Worm; and means for rotating saidworm about said second axis, whereby said stop housing may be angularly shifted to angularlyshift the location of the point of engagement of said stop lugs.

9. In a stop device for a machine tool including a carriage and a rotatable screw for moving said carriage, the combination of a cylindrical member mounted on said screw coaxially therewith for rotation with said screw and for sliding movement therealong, said cylindrical member having external screw threads formed on the exterior thereof and disposed coaxially with said screw;

a stop housing mounted for independentV rotation coaxially with said screw, said stop housing being internally screw threaded to receive said screw threads on said cylindrical member; means on said cylindrical member dening an axially extending stop lug; means on said stop housing dening an axially extending stop lug disposed in a position to be engaged by the stop lug on said cylindrical member, Asaid stop housing having worm gear teeth formed on the exterior periphery thereof; a worm mounted for rotation about an axis eccentrically disposed with respect to lsaid worm, whereby rotation of said worm about said axis moves said worm from a position spaced from said stop housing to a position engaging said worm with said worm gear teeth to hold vsaid stop housing against rotation; control means for rotating said worm about said axis; and spring urged detent means for yieldably holding said control means in said releasing and holding positions. Y

GLYNN H, WILLIAMS. 

